Half-integer spin fermions are constrained by the Pauli exclusion principle whereas integer spin bosons are not. The electron is a fermion with electron spin 1/2. In quantum mechanics, spin is an intrinsic property of all elementary particles. Fermions, the particles that constitute ordinary matter, have half-integer spin. In quantum mechanics and particle physics, spin is an intrinsic form of angular momentum . The spin-statistics theorem states (1) that particles with half-integer spin (fermions) obey Fermi–Dirac statistics and the Pauli Exclusion Principle, and .
An element of answer is that the tensor product of an even number of copies of the fundamental irrep of s u (2), which describes spin- 1 / 2. The "Standard Model" puts many of these features in by hand. What is known is why particles have to have either integer or half-integer spin, and why the former . Spin is a quantum number, and it takes half-integer or integer values. A fermion ( half-integer spin particle) obeys the Pauli exclusion principle.
No. These particles do not spin. Q: Then why we call it "spin"? A: Bad choice (or rather a choice which causes lots of confusion). It was found that elementary. Does it have any physical significance, analogous to the spin of a planet? particles that, like the electron, have half-integer spins (half-integer multiples of.